1. Field of the Invention
This invention relates to a mobile radio terminal apparatus having two radio connection schemes.
2. Description of the Related Art
As a mobile radio system having two radio connection schemes, the cdma (Code Division Multiple Access) 2000 is known.
The cdma2000 system is capable of making radio connection between a mobile station and a base station in two schemes, i.e. 1x communication scheme (hereinafter called “1x”) and 1xEV-DO communication scheme (hereinafter called “1xEV-DO”).
In the 1x, a speech service, SMS (Short Message Service) and a packet communication service having a download speed of about 100 kbps are provided. The 1xEV-DO is employed only to provide a packet communication service having a download speed of higher than 100 kbps. To improve the radio use efficiency of the 1xEV-DO packet communication service, the 1x and 1xEV-DO services are provided at mutually different frequencies.
In a mobile radio terminal apparatus employed in a conventional mobile radio system having two radio connection schemes, however, much battery power is consumed at simultaneous standby in the two radio connection schemes.